Dan Heath is an American bestselling author, speaker and fellow at Duke University's CASE center. Dan chats with the Armchair Expert about why certain ideas stick, the emotionality behind urban legends and the benefit of thinking upstream. Dax implores those to think about the financial benefits to upstream social reform and Dan explains that every system is designed for its outcome. The two talk about systemic preventions that have a lasting impact, getting caught in a bad plan loop and they commiserate about being older dads.